The present application relates generally to apparatus and methods for removing dross from the surface of liquid or molten solder.
During normal containment of liquid solder in a solder reservoir such as that used by a wavesolder device, a metallic oxide forms which is referred to as dross. The dross floats on the solder surface and must periodically be removed from the solder reservoir to prevent contamination of the solder. The manual removal of the dross results in machine down time to remove the dross from the solder reservoir. This machine down time can result in a high cost of ownership due to frequent maintenance to remove these oxides.
One prior art device is a wavesolder designed so that the dross flows into an area at one end of the solder pot reservoir such that a machine operator will manually scoop out the generated dross into a basket for removal. However, the manual removal of the dross can still be time consuming.
Other devices allow the removal of dross from the surface, such as apparatus shown in U.S. Pat. No. 5,087,356 to Webb, U.S. Pat. No. 4,509,670 to Cammarata and U.S. Pat. No. 3,980,219 to Schmid. However, these devices do not function optimally because they in part do not provide for the reclamation of excess solder from collected dross.
An automatic dross removal apparatus, which can be used with a solder wave apparatus, generally includes a reservoir having a cavity for containing liquid solder, dross removal apparatus having a first end extending within the cavity of the reservoir for removing dross on the surface of the liquid solder, and a motor engaged with the dross removal apparatus. In one embodiment of the invention, the dross is automatically removed by a conveyor driven by a motor. In another embodiment of the invention, the dross is automatically removed by a motor driven receptacle. Means for moving the dross from one part of the solder reservoir to another, such as a pump, a nozzle, a sloped surface or channel, a paddle or a moving edge, can be included. Preferably, a computer is used to control the automatic dross removal. The dross can be placed in a dross separation device which can include apparatus for processing the dross to remove any remaining solder.
An advantage of embodiments of the present invention is that a machine having a reservoir of solder, such as a wavesoldering device, does not have to be shut down to remove dross from the surface of the solder.
Another advantage of embodiments of the present invention is that dross can be removed from a solder reservoir without operator interaction, which creates a more maintenance free machine.